Tube support



TUBE SUPPORT Filed Nov. 29, 19'41 4 sheets-sheet 1 1 1 ai I 1 1 1 5 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 i 1 1 1 1 l I 4Sheets-Sheet 2 Ely/77201157 [[IllI TUBE SUPPORT Filed NOV. 29, 1941 W.C. HENSEL EVAL Mmh 2s, 1944.

March 28, 1944.

w. c. HENsEL ETAL 2,345g257 TUBE SUPPORT Filed Nov. 29, 1941 4Sheets-Sheet 5 March 28, 1944 w. c. HENSELYETAL l 2,345,257

TUBE SUPPORT Filed NOV. v29, 1941 4 Sheets-Sheet 4 cil Patented Mar. 28,1944 v 2,345,257 TUBE SUPPORT walter c. Hensel and Lev A. Mekler,Chicago, nl., assignors to Universal Oil Products Company, Chicago,Ill., a corporation of Delaware Application November 29, 1941, SerialNo. .4.2.1,019

12 Claims. (Cl. 122-510) The invention relates to supporting means for asubstantially vertical bank of horizontally disposed heating tubes. Thefeatures of the improved type Aof supporting means provided by theinvention are particularly advantageous as applied to the-tubular iluidconduits of Oil heaters, boilers and the like, which tubes are subjectedto high furnace temperatures and are of suillcient length in the heatingzone to require one or more supports intermediate their ends.

The invention provides both intermediate and end supporting means for atube bank of the nature above mentioned, as well as means for sealingthe tube header compartment of the furnace from the heating zone thereofin which the intermediate tube supports are disposed.

In supporting a vertical bank of horizontally disposed tubes whichtraverse a high temperature heating zone in a furnace and are ofsufcient length to require intermediate supports disposed within saidheating zone, it is convenient to construct the intermediate supportsoi.' metal or metallic alloy which retains good strength at thetemperatures employed in the heating zone and is otherwise capable ofwithstanding oxidizing conditions and the like which may be encountered,so that the supports may be left. bare or uninsulated and are exposed onall sides to the temperature conditions prevailing in the heating zone.The end tube supports, on the other hand, conventionally comprise tubeYsheets which serve as a partition between the heating zone and theunheated compartments of the furnace in which the tube headers or returnbends are disposed. The end tube supports are, therefore, subjected tothe high temperature conditions prevailing in the heating zone on onlyone side or, in some instances, are insulated on the heating zone sidein order that they may be constructed of less expensive material thanthe bare intermediate supports andvto prevent excessive heat losstherethrough. In service such an arrangement brings about differentialexpansion and contraction' upon heating and cooling between theintermediate supports and the end supports. As the furnace is brought upto temperature, the intermediate supports, being subjected to a highertemperature than the end supports, expand a greater amount and becomelonger than the end supports. If the tube bank is suspended, (l. e.,with the supporting means xed at the top and free to expand in adownward direction) the members of the intermediate supports upon whichthe tubes rest when the latter are cold will, when heated, expand awayfrom the tubes and leave them unsupported. If the tube bank is supportedfrom the bottom (i. e., the supporting means fixed at the bottom andfree to expand in an upv er compartments and allowing the tube to oat inthe end tube sheets by providing the latter with elongated tubeopenings. However, such an arrangement brings aboutv another undesirablecondition due to the lack of supporting means at at the end of the tubesand the weight of the return bends or headers, the unsupported ends ofthe tubes and the headers being carried by the intermediate supportsnearest the tube sheets and giving a cantilever action which tends tobow the tubes upward between the end-most intermediate supports. Thismay bring about penna--i nent distortion to the tubes and render themdiiiicult to clean, as well as setting up undesirable stresses in thetube walls. This also renders any intermediate supports, other thanthose nearest the tube sheets, of little or no utility during normaloperation of the heater so that the two end-most tube supports must besufficiently strong to carry substantially the entire weight of the tubebank.

' The improved .supporting means provided by the invention obviates allof the diculties above.

mentioned.' We utilize bare or uninsulated intermediate tube supports ofsuitable high-temperature-resistant metal or alloy and of specialconstruction which prevents springing of thel tubes from theintermediate supports, but permits the tubes to be lifted onto and fromthe intermediate supports in assembling the tube bank and in replacingworn out or damaged tubes. We also employ tube sheets between the headercompartments and the heating zone which are preferably insulated on theheating zone side and` are provided with elongated tube ports whichpermit free upward and downward movement of the tubes at the tubesheets, the latter functioning as partitions which separate the heatingzone from the header compartments. We utilize the headers or returnbends, which connect the adjacent tubes of 4the bank at their oppositeends,

` by the lin in the accompanying diagrammatic drawings. s

In the drawings, Figure 1 is a sectional elevation of a. portion of aheater showing one end and an intermediate' portion of a tube banksupported as provided by the invention.

Figure 2 is a view taken along line- 2-2 in Figure 1, showing some ofthe lowermost tubes of the bank in cross section and showing a frontelevation of the lower end of one of the intermediate tube supports.

Figure 3 is a view of a portion of. the tube bank at an intermediatesupport and is taken along line 3 2 in Figure 2l Figure 4 is an enlargeddetail showing, in front elevation, a portion of the Vintermediatesupport v' illustrated in Figures 1, 2 and 3. v Figure 5 is a sideelevation of that portion of the support iiiustrad in Figure 4, with theimpe 6 omitted.

Figure 6 is a sectional elevation illustrating return bends such asprovided by the invention for use in a bank comprising adjacent.vertical rows of staggered tubes with the adjacent tubes in oppositerows connected in series. This section is taken along a plane winch cutsthrough the tubes adjacent the return bends, as'indicated by the line6--6 in Figure 1. y

Figure '1 shows an enlarged detail of one specinc form of linkage meansjoining two adjacent return bends such as provided by the invention.

Figure 8 is a view taken from the plane indicated by the line 8 8 inFigure 7.

Figure 9 is a sectional elevation similar to that of Figure 6butillustrating return bends such as provided by the invention as usedfor connecting adjacent. superimposed, horizontal tubes in a verticalrow. This section. is taken. as in Figure Figure 1 0 shows an enlargeddetail of an alterwhich are insulated in the heating zoneras indicatedat 23, and separate the latter fromf-the 'I he entire furnace structureis supported on a suitable foundation y header compartments 25.

2 I The heater may be fired in any desired manner.\ The 'firing means'donot comprise a novel part of the invention, and is not illustrated.

Referring particularly to Figures 2 to 5 inclusive, the intermediatetube support I, -as here illustrated, comprises a substantially I-shapedmember which forms the main body of the support, having opposite flangesjoined by an open.-

work web. Along the outer face 'of each of the flanges, brackets 4 and'5 are provided at spaced intervals along kthe length of the flanges. Thevertical distanceV between corresponding portions of adjacent brackets 4on the same flange corresponds to the vertical center to center distancebetween the vertically aligned, horizontally disposed tubes Iiv in eachrow thereof disposed on opposite sides of the support, as illustrated.'I'he vertical distance between corresponding portions of the adjacentbrackets 4 on the opposite flanges, corresponds to half the verticalcenter to center distance between the adjacent tubes -in each row.

The same applies to the distance between the corresponding portions ofbrackets 5. The adjacent brackets 4 and 5 on the same flange arecomplementary, the tubes 6 resting upon the pper curved surface ofbrackets 4, and brackets serving as anchorsv for the upper ends of thesubstan tially semicircular members 1, the lower ends of which areanchored in the supporting brackets 4.

Members 1, which serve to prevent tube 6 from springing from thesupportingstructure due to any tendency of the tubes to bow when heated,may be tubes or solid rods of circular cross-section curved Ato adiameter somewhat larger than the outsidediamgser of tube 6. The membersI each denne slighuy 'more than half a circle so 4 and i, they cannot beforced therefrom by the 6, along a plane which cuts through the tubesadjacent the return bends.

nate form of linkage means between two adjacent return bends.

Figure 11 represents a view taken from the piane indicated by the uneli-i i in Figure io.

Figure l2 is a sectional view of a portion of the tube sheet at one endof the heater. 'Ihe section being taken [along a plane which cutsthrough the tubes adjacent the return bends -as indicated |2--I2 inFigure 1. 1 Figure 3 is a sectional view taken along line Il-Ilin Figure12.

Referring to Figure 1, the tubular fluid conduits s are supported `atspaced ppints within the heating rane of the furnace structure byintermediate supports I. When the` furnace is fired,

the linkage members I I and AI2 attached to the return bends Il take upthe`support of the opposite ends of the hibes. The intermediate supportsand the return bends as well-asumel tube sheet Il are suspended fromsuitable members 2l as shown. The heating'wne of the lateral thrust oftubes 5 when the latter tend to bow outward from the support. However,the form of the brackets and members l make the latter readilydetachable from the brackets when it is desired to place a tube on orremove it from the supporting structure. by rotating member 'I in thedirection indicated bythe arrow shown with the solid line in Figure 4,forcing'its upper end farther into opening 9 y I of barcket 5x andreleasing its lower end from the opening 8 in bracket 4. Then, byturning member 'I'to .the approximate position indicated by the dottedlines in Figure 5 sc that its lower end clears bracket 4, it may berotated 'in the opposite direction, indicated by the dotted arrow inFigure 4 until its upper end is free of opening l in bracketl l, thusreleasing member 'I from-the brackets and permitting tube 6 to be liftedupward and outward from the support, the distance between the outer endsof adjacent brackets 4 and l being somewhat greater than the outsidediameter of the tube. 1

Referring now to Figures 6, 'I and 8 of the drawings, the-'tubes 6terminate inthe return bends Il. Angularly attached to one side oftheVreturn bend is a single lug II and to the opposite side of the returnbend a forked, lug or .two parallel lugs. I2 are attached and-soarranged ythat the n single lug on the adjacent return. bend-is receivedstructure is enclosed by refractory sidewalls, not V- shown inthis view,alefractory roof22.- a refractory oor 24 and tube sheets, such as shownat Il, '*15 between the lugs or forks I2. "ier'tictillvy elQngated holesIl and Il'4 are through lugs II -andIl respectively 'to receive' `a'Ihis is accomplished which is of substantially smaller diameter thanthe length of said holes and is retainedv in position by cotter keys orby any other desired means. The vertical center to center distancebetween the holes in the lugs on opposite sides of the return bend isequal to the center to center distance between the vertically alignedhorizontally disposed tubes 6, as indicated by the dimension A in Figure7. The difference in the diameters of the pin I4 and the verticaldimension of holes I3 and I3'v substantially corresponds to theexpansion which will occur between tube centers in the intermediate tubesupports, when heated, so that when the intermediate tube supportsexpand during heating, this difference is taken up, thereby causing thetube return bends IG to assume the support of their respective tubes andall return bends and tubes disposed therebelow. By thus supporting thetube ends when they are in a heated state, the possibility of theirbecoming warped or bowed is minimized, and stresses within the tubewalls dueto bending are thus obviated. This also helps to decreasepermanent distortion of the tubes and thereby lengthens their usefullife and facilitates the removal of carbonaceous or calcarious depositstherefrom.

Figure 9 shows a linkage arrangement similar to that shown in Figure 6except that the return bends I' of Figure 9 connect adjacenthorizontally disposed tubes 6 in a vertical row thereof. The lugs II andI2' are disposed at opposite and 2B in this gure. With this arrangement,l

as in that shown Figure 7, the pins which connect the lugs on the returnbends are smaller than the openings provided for the pins.

Figures 10 and .l1 show an alternative form of linkage means wherein thelI-shaped member I8 engages the slots i1 and I1 in the return bendextensions or lugs I5 and I5 respectively on the return bends I0" whenthe intermediate tube supports expand. The members I6 and slots i1 andI1 are of such relative size that the return bends are loosely connectedwhen the tube bank is cold, the slack being taken up when theintermediate tube supports expand so that the return bends act as endsupports for the tubes. 'Ihis form of linkage arrangement may also besubstituted, when desired, for that shown in the return bend arrangementof Figure 9.

Referring to Figures 12 and 13, the tubes 6 extend through thevertically elongated openings 26 in the tube Sheet I8. Adjacent theouter surface of the tube sheet the tubes are encompassed by the closureplates- 21 which are retained in slidably movable relationship to thetube sheet by washers 28, the tubular spacing members 29 and the bolts30 which engage the tube sheet and pass through the vertically elongatedcentral openings 3| in plate`21. The tubes and closure plates are thusfree to move up and down within the limits necessary to accommodatelongitudinal expansion and contraction of the intermediate supports, andthe tubes are free to expand and contract longitudinally through thetube openings in lthe tube sheets and closure plates without moving thelatter from its position of sliding engagement with the tube sheet.Using this feature of the invention, it is possible to allow for thelongitudinal expansion of both the intermediate supports and the tubesthemselves and still maintain a substantial seal between the tube heatercompartment and the heated portion of the furnace.

We claim as our invention: p

1. In a heater for fluids having a bank of tubular fluid conduitsdisposed within a heated zone of the structure and provided at theirends with terminal fittings which connect adjacent tubes of the bank andare disposed outside said heated zone, means comprising bare metalmembers disposed within said heated zone for supporting said tubesintermediate their ends, means comprising metal tube sheets insulatedfrom said heated zone for separating the latter from that zone of thestructure in which said terminal ttings are disposed, and means looselyinterconnecting said terminal fittings when the intermediate supportsare cold and which tighten to support the tubes at their ends when theintermediate supports are hot.

2. In a heater for fluids having a bank of tubular uid conduits disposedwithin a heated zone of the structure and provided at their ends withterminal ttings whichconnect adjacent tubes of the bank for the flow offluid therethrough and are disposed outside said heated zone, meanscom-l prising bare metal members disposed in said heated zone andfreeat. one end, for supporting the tubes intermediate their ends, meansloosely interconnecting said terminal fittings when the intermediatesupports are cold and which tighten to support the tubes at their endswhen the intermediate supports are hot, and means comprising metalplates provided with openings through which the tubes extend andinsulated from said heated zone, for separating the latter from thatzone of the structure in which said terminal fittings are disposed.

3. The structure' defined in claim 2 wherein said separating means andsaidend-supporting means are constructed and arranged to permitexpansion and contraction of the tube bank and of said intermediatesupporting members.

l 4. In a heater for iluids having a bank of super-imposed, horizontallydisposed tubular fluid conduits extending through a heated zone ofthestructure and provided at their opposite ends with terminal ittingsdisposed outside said heated zone and connecting adjacent tubes of thebank for the flow of luid therethrough, means comprising tube sheetsprovided with openings larger than the tubes and through which saidtubes extend for separating said heated zone from that zone in which theterminal ttings are disposed, said tube sheets being insulated from theheated zone, means comprising bare metal members disposed Within saidheated zone and free at one end, for supporting the tubes intermediatetheir opposite ends, and means on said terminal littings which looselyinterconnect the same when theintermediate supports are cold and whichtighten to support the tubes, at their ends when the intermediatesupports are hot. l

5. The structure deiined in claim 4 wherein the last named means includelugs on said terminal fittings and links connecting adjacent ttings atsaid lugs.

6. The structure dened in claim 4 wherein said intermediatetube-supporting means comprise elongated members having verticallyspacedbrackets between which the tubes are received and members spanningadjacent brackets and detachably secured thereto for restrainingspringing of the tubes from between said brackets. l

'1. The structure dened in cham 1 wherein the intermediatetube-supporting means comprises an elongated metal member, pairs ofbrackets on said member spaced apart to permit the passage of a tubetherebetween, and an auxiliary member spanning the distance between eachpair of said brackets and detachably secured thereto in such a manner asto prevent springing of the tubes from between the brackets when saidaux iliary members are in place.

8. Thestructure deiined in claim 1 wherein the intermediatetube-supporting means comprises an elongated metal member anchored atone end and free at its opposite end to permit longitudinal expansionand contraction thereof, supporting ybrackets for the tubes disposed onsaid member at spaced points along its length, auxiliary bracketsdisposed on said member between and spaced from said supportingbrackets, and other auxiliary members spanning the distance between thesupporting brackets and the adjacent auxillhang adapted to nt withinsaid openings and the shape, size and curved contour of said openingsand retaining members being such that the latter resist outward bowingof the tubes but are detachable from the brackets by a combination ofmotions including partial rotation of the retaining members. F

10. Supporting means for the ends of tubes in a bank of substantiallyhorizontal tubular fluid conduits, said means comprising terminal ttingson said tubes interconnecting `adjacent tubes of the bank for the flowof fluid therethrough, and means for detachably interengaging adjacentfittings comprising lugs on said fittings provided conduits, said meanscomprising terminal ttings iary brackets and detachably secured theretoin such a manner as to restrain springing or the tubes from between saidbrackets.

9. In combination with a bank of substantially horizontal tubular fluidconduits disposed within y being adapted to receive and retain theopposite` ends of an elongated rigid member of curved contour spanningthe distance between said pair of brackets, and detachably secured tothe latter to retain one of said tubular members therebetween, thebrackets being provided with openings therein of cu'rved contourcorresponding to that of the ends of said retaining member, said endswith regsterable openings therethrough, and removable pins of smallersize than said openings and receivable thereinfor interengaging adjacentfittings at said lugs.

, 11. Supporting means f or the ends of tubes in a bank of substantiallyhorizontal tubular fluid on said tubes interconnecting adjacent tubes ofthe bank for the flow of fluid therethrough, and means for detachablyinterengaging adjacent fittings comprising lugs on said ttings providedwith slotted openings therein and links extending between and detachably.engaged with the slotted openings in the lugs of adjacent fittings.

12. Supporting means for the ends of tubes in a bank of substantiallyhorizontal tubular fluid conduits, said means comprising terminalfittings on said tubes interconnecting adjacent tubes of the bank forthe flow of fluid therethrough, and means for detachably interengagingadjacent fittings comprising lugs on said fittings provided with slottedopenings therein and links. extending between and detachably engagedwithB the slotted openings in the lugs of adjacent fittings, said linksyand openings being of such form and .relative size that the adjacentfittings are loosely engaged when the tube bank is cold and tightlyengagedv when the tube bank is hot.

WALTER c. HENSEL. LEV A. MEKLER.

